 /*******************************************************************************
  * Copyright (c) 2000, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.text.edits;

 /**
  * A visitor for text edits.
  * <p>
  * For each different concrete text edit type <it>T</it> there is a method:
  * <ul>
  * <li><code>public boolean visit(<it>T</it> node)</code> - Visits the given edit to
  * perform some arbitrary operation. If <code>true </code> is returned, the given edit's
  * child edits will be visited next; however, if <code>false</code> is returned, the
  * given edit's child edits will not be visited. The default implementation provided by
  * this class calls a generic method <code>visitNode(<it>TextEdit</it> node)</code>.
  * Subclasses may reimplement these method as needed.</li>
  * </ul>
  * </p>
  * <p>
  * In addition, there are methods for visiting text edits in the
  * abstract, regardless of node type:
  * <ul>
  * <li><code>public void preVisit(TextEdit edit)</code> - Visits
  * the given edit to perform some arbitrary operation.
  * This method is invoked prior to the appropriate type-specific
  * <code>visit</code> method.
  * The default implementation of this method does nothing.
  * Subclasses may reimplement this method as needed.</li>
  *
  * <li><code>public void postVisit(TextEdit edit)</code> - Visits
  * the given edit to perform some arbitrary operation.
  * This method is invoked after the appropriate type-specific
  * <code>endVisit</code> method.
  * The default implementation of this method does nothing.
  * Subclasses may reimplement this method as needed.</li>
  * </ul>
  * </p>
  * <p>
  * For edits with children, the child nodes are visited in increasing order.
  * </p>
  *
  * @see TextEdit#accept(TextEditVisitor)
  * @since 3.0
  */
 public class TextEditVisitor {

     /**
      * Visits the given text edit prior to the type-specific visit.
      * (before <code>visit</code>).
      * <p>
      * The default implementation does nothing. Subclasses may reimplement.
      * </p>
      *
      * @param edit the node to visit
      */
     public void preVisit(TextEdit edit) {
         // default implementation: do nothing
 }

     /**
      * Visits the given text edit following the type-specific visit
      * (after <code>endVisit</code>).
      * <p>
      * The default implementation does nothing. Subclasses may reimplement.
      * </p>
      *
      * @param edit the node to visit
      */
     public void postVisit(TextEdit edit) {
         // default implementation: do nothing
 }

     /**
      * Visits the given text edit. This method is called by default from
      * type-specific visits. It is not called by an edit's accept method.
      * The default implementation returns <code>true</code>.
      *
      * @param edit the node to visit
      * @return If <code>true</code> is returned, the given node's child
      * nodes will be visited next; however, if <code>false</code> is
      * returned, the given node's child nodes will not be visited.
      */
     public boolean visitNode(TextEdit edit) {
         return true;
     }

     /**
      * Visits a <code>CopySourceEdit</code> instance.
      *
      * @param edit the node to visit
      * @return If <code>true</code> is returned, the given node's child
      * nodes will be visited next; however, if <code>false</code> is
      * returned, the given node's child nodes will not be visited.
      */
     public boolean visit(CopySourceEdit edit) {
         return visitNode(edit);
     }

     /**
      * Visits a <code>CopyTargetEdit</code> instance.
      *
      * @param edit the node to visit
      * @return If <code>true</code> is returned, the given node's child
      * nodes will be visited next; however, if <code>false</code> is
      * returned, the given node's child nodes will not be visited.
      */
     public boolean visit(CopyTargetEdit edit) {
         return visitNode(edit);
     }

     /**
      * Visits a <code>MoveSourceEdit</code> instance.
      *
      * @param edit the node to visit
      * @return If <code>true</code> is returned, the given node's child
      * nodes will be visited next; however, if <code>false</code> is
      * returned, the given node's child nodes will not be visited.
      */
     public boolean visit(MoveSourceEdit edit) {
         return visitNode(edit);
     }

     /**
      * Visits a <code>MoveTargetEdit</code> instance.
      *
      * @param edit the node to visit
      * @return If <code>true</code> is returned, the given node's child
      * nodes will be visited next; however, if <code>false</code> is
      * returned, the given node's child nodes will not be visited.
      */
     public boolean visit(MoveTargetEdit edit) {
         return visitNode(edit);
     }

     /**
      * Visits a <code>RangeMarker</code> instance.
      *
      * @param edit the node to visit
      * @return If <code>true</code> is returned, the given node's child
      * nodes will be visited next; however, if <code>false</code> is
      * returned, the given node's child nodes will not be visited.
      */
     public boolean visit(RangeMarker edit) {
         return visitNode(edit);
     }

     /**
      * Visits a <code>CopyingRangeMarker</code> instance.
      *
      * @param edit the node to visit
      * @return If <code>true</code> is returned, the given node's child
      * nodes will be visited next; however, if <code>false</code> is
      * returned, the given node's child nodes will not be visited.
      */
     public boolean visit(CopyingRangeMarker edit) {
         return visitNode(edit);
     }

     /**
      * Visits a <code>DeleteEdit</code> instance.
      *
      * @param edit the node to visit
      * @return If <code>true</code> is returned, the given node's child
      * nodes will be visited next; however, if <code>false</code> is
      * returned, the given node's child nodes will not be visited.
      */
     public boolean visit(DeleteEdit edit) {
         return visitNode(edit);
     }

     /**
      * Visits a <code>InsertEdit</code> instance.
      *
      * @param edit the node to visit
      * @return If <code>true</code> is returned, the given node's child
      * nodes will be visited next; however, if <code>false</code> is
      * returned, the given node's child nodes will not be visited.
      */
     public boolean visit(InsertEdit edit) {
         return visitNode(edit);
     }

     /**
      * Visits a <code>ReplaceEdit</code> instance.
      *
      * @param edit the node to visit
      * @return If <code>true</code> is returned, the given node's child
      * nodes will be visited next; however, if <code>false</code> is
      * returned, the given node's child nodes will not be visited.
      */
     public boolean visit(ReplaceEdit edit) {
         return visitNode(edit);
     }

     /**
      * Visits a <code>UndoEdit</code> instance.
      *
      * @param edit the node to visit
      * @return If <code>true</code> is returned, the given node's child
      * nodes will be visited next; however, if <code>false</code> is
      * returned, the given node's child nodes will not be visited.
      */
     public boolean visit(UndoEdit edit) {
         return visitNode(edit);
     }

     /**
      * Visits a <code>MultiTextEdit</code> instance.
      *
      * @param edit the node to visit
      * @return If <code>true</code> is returned, the given node's child
      * nodes will be visited next; however, if <code>false</code> is
      * returned, the given node's child nodes will not be visited.
      */
     public boolean visit(MultiTextEdit edit) {
         return visitNode(edit);
     }
 }

